Maybe there is an interesting story to be written concerning another heavy metal - mercury and its use in dental amalgam.
Aside from whether it's prudent - irrespective of current evidence - to permanently store a compound containing 50% of a neurotoxin an inch or two from your brain, the release of almost 3,000 kilograms (6,613 lbs.) of mercury (data for 2005 alone) into the atmosphere from crematoria is cause for worry. Wikipedia notes that 'Good empirical data on the magnitude of mercury emissions from crematoria, however, are lacking'. No one is interested I guess.